During automatic series production, motor vehicle wheels having tubeless tires are usually filled with compressed air in an automatic tire inflation station which is an integral part of the assembly line. In this process the rim with the tire fitted is placed on a suitable support plate which seals the wheel from beneath during the filling process. A filling bell is positioned on the upper side of the tire, said bell sealing the tire and the rim from above, and through which the sidewall of the tire is pressed downwards during the filling process until an annular gap is formed between the tire bead and the rim, through which the compressed air passed into the filling bell can flow into the tire. The compressed air flowing into the tire presses the tire against the base plate and the filling bell with considerable force. Once the filling pressure is reached, the filling bell is raised, causing the sidewalls of the tire to move apart in the axial direction until the tire beads have taken up their respective seat position on the rim. For the purpose of such a filling operation, the filling bell must have an opening with a diameter which is on the one hand large enough so that the filling bell does not come into contact with the rim, but can be placed over the rim. On the other hand, the diameter of the opening must not be so large that the filling bell touches the upper sidewall of the tire radially apart from its highest point. The filling bell would in this case impede radial movement of the tire, which might cause the tire bead not to spring back into its seat correctly. A filling bell is thus only suited to a limited range of motor vehicle wheel sizes.
In a tire inflating station which is known in the art from DE 100 07 019 A1, the wheel/tire arrangement is stored in the tire inflating station such that it is positioned with the bottom side surface of the tire sealed on a base plate. A tire filling bell is located above the upper side of the wheel/tire arrangement, said bell being lowered for the tire inflation process and the tire sidewall being pressed away from the rim with its annular edge so that an annular space is formed between the sidewall of the tire and the wheel rim, via which the tire is filled with compressed air. Wheels with different tire sizes and/or rim sizes can be filled to a restricted extent due to the formation of two filling bells fitted inside one another with two different diameters.
To extend the range of tire sizes to be filled in the same tire inflating station, a tire inflating station of the type mentioned at the outset and known from EP 1 671 820 B1 comprises a tire filling bell having a plurality of filling rings of different diameters, a filling ring with an appropriate diameter being used according to the size of the tire. The filling rings are fixed in an annular manner to holders on a central motion device and can be moved with said motion device around a circle into the centered position with respect to the axis of rotation of the wheel and axially. A respective filling ring which has been moved into the centered position forms the filling bell together with a filling plate and can be moved with one edge against the side surface of a tire to be inflated. The space required for this known tire inflating station is regarded as a disadvantage.
The tire inflating station in DE10 2009 046 195 B3 is a filling device having a carrier plate arranged on the underside of said device, said carrier plate being mounted in a straight guide so that it can move to and fro along an axis between a plurality of positions, the filling rings being fixed in a gas-tight manner one behind the other on the underside of the carrier plate, when viewed in the direction of motion, the carrier plate comprising a respective through-opening inside the filling rings, and another of the through-openings being connected to the filling opening for the filling device positioned on the upper side of the carrier plate in each of the plurality of positions of the carrier plate. The space required to apply more than three filling rings to the carrier plate is also disadvantageous in this case.